1. Field of the Invention
The present invention relates to a method for producing L-phenylalanine by fermentation.
2. Brief Description of the Prior Art
It is known that tyrosine auxotrophic mutants of the genera Micrococcus and Brevibacterium (Japanese Published Examined Patent Application No. 6345/1952), and mutants of the genera Brevibacterium and Corynebacterium resistant to phenylalanine analogue (U.S. Pat. No. 3,660,235) produce L-phenylalanine. The most efficient known microorganism producer of phenylalanine is Brevibacterium lactofermentum AJ 3437 (FERM-P 1914), which is resistant to p-fluorophenylalanine and 5-methyltryptophan and which requires tyrosine and methionine for growth. This strain produced 2.20 g/dl phenylalanine from 13 g/dl glucose. However, the yield of phenylalanine in this best known method is still insufficient to fulfill commercial requirements. Therefore, a need continues to exist for a method for the production of phenylalanine by fermentation in high yields.